From the spring documentation :
@Cacheable(value="bookCache", key="isbn")
public Book findBook(ISBN isbn, boolean checkWarehouse, boolean includeUsed)
How can I specify @Cachable
to use isbn
and checkWarehouse
as key?
This will work
@Cacheable(value="bookCache", key="#checkwarehouse.toString().append(#isbn.toString())")
You can use a Spring-EL expression, for eg on JDK 1.7:
@Cacheable(value="bookCache", key="T(java.util.Objects).hash(#p0,#p1, #p2)")
Use this
@Cacheable(value="bookCache", key="#isbn + '_' + #checkWarehouse + '_' + #includeUsed")
After some limited testing with Spring 3.2, it seems one can use a SpEL list: {..., ..., ...}
. This can also include null
values. Spring passes the list as the key to the actual cache implementation. When using Ehcache, such will at some point invoke List#hashCode(), which takes all its items into account. (I am not sure if Ehcache only relies on the hash code.)
I use this for a shared cache, in which I include the method name in the key as well, which the Spring default key generator does not include. This way I can easily wipe the (single) cache, without (too much...) risking matching keys for different methods. Like:
@Cacheable(value="bookCache",
key="{ #root.methodName, #isbn?.id, #checkWarehouse }")
public Book findBook(ISBN isbn, boolean checkWarehouse)
...
@Cacheable(value="bookCache",
key="{ #root.methodName, #asin, #checkWarehouse }")
public Book findBookByAmazonId(String asin, boolean checkWarehouse)
...
Of course, if many methods need this and you're always using all parameters for your key, then one can also define a custom key generator that includes the class and method name:
<cache:annotation-driven mode="..." key-generator="cacheKeyGenerator" />
<bean id="cacheKeyGenerator" class="net.example.cache.CacheKeyGenerator" />
...with:
public class CacheKeyGenerator
implements org.springframework.cache.interceptor.KeyGenerator {
@Override
public Object generate(final Object target, final Method method,
final Object... params) {
final List<Object> key = new ArrayList<>();
key.add(method.getDeclaringClass().getName());
key.add(method.getName());
for (final Object o : params) {
key.add(o);
}
return key;
}
}
You can use Spring SimpleKey class
@Cacheable(value = "bookCache", key = "new org.springframework.cache.interceptor.SimpleKey(#isbn, #checkWarehouse)")
Source: Stackoverflow.com